In the past, various types of case handling machines have been developed. Case handling machines include machines for assembling or erecting cases, machines for sealing cases and machines for placing inserts in cases, plus various combinations thereof. For example, some case handling machines both assemble or erect cases and, then, partially seal the erected cases. Other case handling machines merely seal cases. In some instances, sealing is accomplished using an adhesively coated tape. In other cases, an adhesive is applied directly to the major and/or minor flaps of the case to be sealed.
The present invention is directed to case handling machines suitable for automatically erecting cases, folding the bottom major flaps of the cases over the bottom minor flaps and attaching the bottom major and minor flaps together using an adhesive. Generically, such machines are known as case set-up and bottom sealing machines. Case set-up and bottom sealing machines are suitable for erecting and bottom sealing open top cases, conventional cases, i.e., cases having top major and minor flaps suitable or closing the top of a case after the case is filled and Tab-Lok cases. Tab-Lok cases are cases having top major and minor flaps that can be positioned so as to overlap the sides of a case when the case is erected. Tabs between a pair of adjacent major and minor flaps maintain the major and minor flaps in the side overlapping position until the joining tab is broken. After the joining tab is broken, the flaps can be folded to close the open top of the case in the same manner as the major and minor flaps of a standard case.
In the past, case set-up and bottom sealing machines have been either entirely manually controlled or semi-automatically controlled. Manually controlled machines are undesirable because they are slow and labor intensive. While semi-automatically controlled machines are faster and, generally, decrease the amount of skilled labor needed, semi-automatically controlled machines have other disadvantages.
The major disadvantage of prior art semi-automatically controlled case set-up and bottom sealing machines is the difficulty in changing the mode of operation of such machines. Mode of opertion changes vary from changes in case length to changes in type of case to be erected and bottom sealed, e.g., Tab-Lok to open top. In order to change the mode of operation of prior art case set-up and bottom sealing machines, various adjustments must be made by a skilled mechanic. Moreover, the mechanical control systems used in prior art machines (which include timing wheels and related mechanical devices) are subject to wear and, thus, relatively frequent adjustment by a skilled mechanic. In addition to the cost attendant to the services of a skilled mechanic, the loss of machine time (e.g., machine downtime) attendant to such changes is greater than desirable. Machine downtime is undesirable for two reasons--the idle time of the machine operator; and, the idle time of employees filling the cases being assembled by the machine. Further, the ability to control the amount and pattern of the glue applied to seal the bottom of cases is severly limited in prior art case set-up and bottom sealing machines. Thus, there is a need for a case set-up and bottom sealing machine having a control system that is not subject to mechanical wear and whose mode of operation can be rapidly changed.